Diffuser arrangment for selfcontained air conditioning unit



March 29, 1955 F. D. STEVENS 2,704,971

DIFFUSER ARRANGEMENT FOR SELF-CONTAINED AIR CONDITIONING UNIT Filed Jan.5, 1949 INVENTOR- United States Patent DIFFUSER ARRANGEMENT FOR SELF-CONTAINED AIR CONDITIONING UNIT Frank D. Stevens, Syracuse, N. Y.,assignor to Carrier Corporation, Syracuse, N. Y., a corporation ofDelaware Application January 5, 1949, Serial No. 69,384

Claims. (CI. 98-40) This invention relates to self-contained airconditioning units and more particularly to a self-contained airconditioning unit including a diffuser for assuring that the dischargeof air from the unit is uniform across the face of the discharge grille.

In self-contained air conditioning units, for example, of the typedisclosed in co-pending application Serial No. 731,363, filed February27, 1947, now Patent No. 2,506,758, issued May 9, 1950, in the name ofHenry S. Woodrulf, the problem exists of assuring uniform distributionof treated air throughout the area of the discharge grille. Generally,such air is discharged from a plenum in the unit. The stream of airentering the plenum strikes the walls thereof and is immediatelydirected to the discharge outlet being concentrated at the center of thegrille rather than being diffused or distributed throughout the plenumchamber to assure uniform discharge across the face of the grille.

The chief object of the present invention is to provide a self-containedair conditioning unit containing a diffuser arrangement which assuresuniform air distribution across the face of the discharge grille.

An object is to provide a self-contained air conditioning unit in whicha diffuser arrangement is disposed about the inlet of the plenum toassure diffusion of entering air throughout the plenum chamber.

A further object is to provide a self-contained air conditioning unitincluding inclined walls disposed about the plenum inlet to direct airentering the plenum throughout the plenum chamber thereby assuringuniform distribution of discharged air across the face of the dischargegrille. Other objects of my invention will be readily perceived from thefollowing description.

This invention relates to a self-contained air conditioning unitincluding in combination a cabinet, a refrigeration system for coolingair drawn within the cabinet, a plenum chamber, a fan for drawing air tobe cooled within the cabinet and through the cooling coil of therefrigeration system, said fan discharging the cooled air within theplenum chamber, and a diffuser arrangement disposed in the plenumchamber surrounding the plenum inlet and serving to diffuse cooled airthroughout the plenum chamber thereby assuring uniform discharge of airacross the plenum outlet.

The attached drawing illustrates a preferred embodiment of my invention,in which Figure 1 is a front elevation of a self-contained airconditioning unit partly broken away to disclose the interiorarrangement;

Figure 2 is a sectional view taken on the line 2-2 of Figure l; and

Figure 3 is a plan view of the diffuser arrangement shown in Figures 1and 2.

Referring to the drawing, there is shown the self-contained airconditioning unit of my invention designated generally by numeral 2.Unit 2 consists of a cabinet 3 forming machine compartment 4, evaporatorcompartment 5 and plenum chamber 6. The refrigerating system 7 isdisposed in compartment 4 and includes a compressor 8, a prime mover 9to actuate compressor 8, and a condenser 10 connected to an evaporator11 disposed in compartment 5 by liquid line 10'. Evaporator 11 isconnected to compressor 8 by suction line 12. Suitable filters 13 aredisposed in compartment 5 to filter air drawn within the cabinet. Incompartment 5 is a grille 14 through which fan 15 induces air withincompartment 5 drawing the induced air through the evaporator in heatexchange relation with the refrigerant therein.

Fan 15 then discharges the cooled air through outlet 16 in compartment 5to the inlet 17 of plenum 6. Considering Figure 2, it will be noted thescroll or casing of fan 15 is not provided with the customary typecutoff which approaches the fan wheel. Instead the scroll itselfapproaches the discharge, eliminating the customary cutoff usuallyemployed in centrifugal fan design, thereby reducing the velocity of theair stream and permitting more satisfactory diffusion of air withinplenum 6 with less noise and also permits direct placement of the fandischarge adjacent to plenum inlet 17.

A diffuser arrangement designated generally at 18 surrounds inlet 17 ofthe plenum. It will be noted that inlet 17 possesses a polygonal shapewith its rear edge approximately three times as wide as its front edgeand that the edge portions connecting the side edges and the front edgeare disposed at angles to the front edge of the inlet. This particularcontour of the opening aids in the diffusion of air throughout theplenum chamber.

Diffuser arrangement 18 includes a substantially vertically extendingfront wall flange 19 secured to the base of plenum. Extending fromflange 19 is a wall member 20 inclined outwardly from flange 19 and awayfrom the inlet 17. Side flanges 21 and 22 are provided forming acontinuation of flange 19 about inlet 17. Flanges 21 and 22 extendsubstantially vertically and at an angle greater than from flange 19.Wall members 23 and 24 extend from flanges 21 and 22 respectively andare inclined outwardly therefrom similarly to member 20. Flanges 25 and26 form continuations of flanges 21 and 22 and extend at an angle ofapproximately 90 to a line drawn horizontally from flange 19. Wallmembers 27 and 28 extend from flanges 25 and 26 and are inclinedoutwardly with respect thereto. Members 27 and 28 are inclined inopposite directions. At the rear of inlet 17 is disposed a substantiallyvertically extending rear wall member 29 completing an inclosure aboutinlet 17.

The air diffuser serves to diffuse air supplied through inlet 17throughout the plenum chamber. Diffusion of treated air throughout theplenum chamber builds a slight pressure in the chamber and assuresuniform distribution of air across the face of the outlet grille 30forming the front surface of plenum 6.

Under some circumstances, it may not be desired to employ a plenumchamber but to use ducts connected to inlet 17 to supply treated air toan area to be conditioned. To avoid special duct shapes under suchconditions, brackets 31 may be provided enabling the diffuser 18 to beremoved and standard ducts to be connected to the inlet.

The present invention provides an air conditioning unit in which air maybe discharged to an area being treated substantially uniformly acrossthe discharge outlet of the unit. Such manner of discharge obviatesdraft and uncomfortable conditions in the area being treated. Thediffuser arrangement may be economically constructed and provides asimple, ready arrangement for assuring diffusion of treated air withinthe plenum.

While I have described and illustrated a preferred embodiment of myinvention, it will be understood my invention is not limited theretosince it may be otherwise embodied within the scope of the followingclaims.

I claim:

1. In a self-contained air conditioning unit, the combination of arefrigeration system to treat air for supply to an area beingconditioned, a fan to draw air within the unit in heat exchange relationwith the evaporator of the system, a plenum chamber having an inlet andan outlet, the outlet being placed in a wall of the chamber disposed atan angle to the wall of the chamber containing the inlet, said fan beingconnected to the plenum chamber inlet and serving to discharge treatedair within the plenum chamber, and a diffuser arrangement disposed inthe plenum chamber about the inlet, said diffuser arrangement comprisinga substantially vertically extending front flange, a front wall memberon said flange inclined outwardly therefrom, side flanges extendingsubstantially vertically and at angles greater than 90 from the frontflange, wall members on said side flanges inclined outwardly from saidside flanges, second side flanges forming continuations of the firstside flanges, and extending at an angle of approximately 90 to a linedrawn horizontally through the front flange, wall members inclinedoutwardly from the second flanges in opposite directions and asubstantially vertically extending rear wall member completing anenclosure about the plenum chamber inlet.

2. A self-contained air conditioning unit according to claim 1 in whichthe fan possesses a scroll without a cut-off and which approaches theinlet of the plenum to permit immediate discharge of air to the plenumchamber, the fan discharge being placed directly adjacent the plenumchamber inlet.

3. In a self-contained air conditioning unit, the combination of arefrigeration system to cool air for supply to an area beingconditioned, a fan to supply treated air to a plenum, said plenumcontaining an inlet in a wall at a substantially right angle to a wallcontaining an outlet, and an air diffuser disposed in the plenumsurrounding the inlet, said diffuser including a substantiallyvertically extending wall member about one side of the inlet,substantially vertically extending flanges about the remaining sides ofthe inlet, and wall members inclined outwardly from said flanges todiffuse entering air throughout the plenum thereby permittingsubstantially uniform distribution of air through the outlet.

4. In a self-contained air conditioning unit, the combination of arefrigeration system to treat air for supply to an area beingconditioned, a fan to draw air within the unit in heat exchange relationwith the evaporator of the system, a plenum chamber having an inlet in awall at a substantially right angle to a wall containing an outlet, saidfan being connected to the plenum chamber inlet and serving to dischargetreated air within the plenum chamber, and a diffuser arrangementdisposed in the plenum chamber about the inlet, said difiuser includinga substantially vertically extending wall member about one side of theinlet, substantially vertically extending flanges disposed about theremaining sides of the inlet, and wall members inclined outw enteringair throughout suring substantially uni across the face of the outlet.

5. In a self-contained air conditionin bination of a refrigeration to anarea being condition to a plenum chamber, a p inlet in a wall at asubstanti containing an outlet, s in spaced rel end of the wal disposedin the pl said diffuser including a s wall member about one side of thvertically extending flanges the inlet, and w flanges to di chamberthere bution of the air through the outlet.

References Cited in the file of this patent UNITED STATES PATENTSFOREIGN PATENTS Great Britain Dec. 12, 1938 Great Britain Apr. 12, 1939Great Britain Aug. 7, 1946 Germany Oct. 7, 1932 all members 1 ardly fromsaid flanges to diffuse the plenum chamber thereby asform distributionof treated air g unit, the comsystem to cool air for ed, a fan to supplytreated air lenum chamber containing an ally right angle to a wall aidinlet further being positioned lls disposed at right angles to the 1containing the outlet, and an air diffuser enum chamber surrounding theinlet, ubstantially vertically extending e inlet, substantially aboutthe remaining nclined outwardly from said se entering air throughout theplenum by permitting substantially uniform distripp y sides of Feb. 12,1935 Jan. 25, 1938

